1. Field of the Invention
This invention relates broadly to laboratory equipment. More particularly, this invention relates to test tubes.
2. State of the Art
Standard test tubes are tubular in shape and have a rounded sealed bottom end and an open top end. The standard test tube design possesses a high degree of utility in laboratory experimentation and research. In fact, it is anticipated that the standard shape test tube will continue to dominate the test tube market due to its simplicity and design familiarity. Yet, this dominance is in spite of drawbacks associated with the standard design.
As a result of the shape of the standard design test tube, standard test tubes require the use of a rack for support, as the tubes cannot stand on their own. In addition, unless the open end of a standard design test tube is closed with a stopper, when the tube is placed on a surface, the contents of the tube will spill out. Therefore, standard design test tubes, regardless of size, generally require the use of a test tube rack to hold the test tubes while being utilized. In addition, when placing a standard test tube into a heated water bath, the standard test tube must first be placed into a test tube rack and then the entire rack must be inserted into the water, such that the standard test tubes are substantially submerged. This results in more time and energy needed to bring the contents of the standard test tubes to the desired temperature. Furthermore, as a substantial portion of the standard test tube is submerged in the water bath, it is difficult to monitor reactions occurring within the test tube. Moreover, when applying heat to a standard test tube, it is common to place the test tube in a clamp and to apply a flame under the test tube. This often provides uneven heating of the contents, as heat is applied primarily only under the bottom of the test tube, and the contents at the bottom of the tube may scorch while the contents higher up in the test tube are not effectively heated. Likewise, standard test tubes cool slowly as cool air will only come into contact with a small surface area of the contents of the tube. In addition, when adding or heating reagents in a standard test tube there is a strong potential for harmful spatter from "bumping" (the rapid evolution of gas bubbles) to occur which can result in sample loss. Furthermore, when adding a substance to a test tube in situations where the substance weight is critical, the substance must first be weighed on weighing paper and then transferred into the test tube. The use of weighing paper results in a loss of substance, as some amount of substance still remains on the weighing paper after the substance has been transferred into the test tube.